Automatic reset flood valve

ABSTRACT

A valve includes a holder having an expandable material. The valve includes a retainer coupled to the holder. The valve further includes an umbrella member with a stem coupled to the holder. The expandable material is adapted to expand in size when absorbing a fluid and translate the umbrella member along an axis of the stem.

CROSS REFERENCE TO RELATED PATENTS

The present U.S. Utility Patent Application claims priority pursuant to35 U.S.C. § 119(e) to U.S. Provisional Application No. 62/617,918,entitled “AUTOMATIC RESET FLOOD VALVE”, filed Jan. 16, 2018, which ishereby incorporated herein by reference in its entirety and made part ofthe present U.S. Utility Patent Application for all purposes.

TECHNICAL FIELD

The present disclosure relates to mechanical aspects of an umbrellavalve device, which may be used as a release mechanism for a batteryenclosure or other enclosure to release any accumulated fluid orpressurized gas from inside the module.

BACKGROUND

Battery enclosures typically include a housing with multiple cellshoused inside. During operation, cells may rupture expelling gas andliquid. Further, undesired fluid or pressurized gas may also fill themodule through failures, such improper sealing when exposed to anexternal water source. Conversely, the battery enclosure may be exposedto water (or other liquid) external to it. In such a circumstance, it isvital to make sure that no external fluids enter the inside of thebattery enclosure as this could cause shorting of the battery cells orwiring, creating an unsafe situation. Thus, there should be an openingor a channel through which this undesired fluid or vapor can be drained.Conventional drains have a valve for selectively releasing fluid frominside of a housing, like a battery enclosure. However, such valves needto be manually operated, and periodic external interventions arenecessary for operation of such valves. Therefore, an improved design ofvalve for such an application is required.

SUMMARY

The present disclosure provides a valve to selectively seal an opening.a valve includes a holder having an expandable material. The valveincludes a retainer coupled to the holder. The valve further includes anumbrella member with a stem coupled to the holder. The expandablematerial is adapted to expand in size when absorbing a fluid andtranslate the umbrella member along an axis of the stem. The expandablematerial may be made of cellulose, silica gel, sodium polyacrylate,other hygroscopic polymers, or another expanding material. Theexpandable material can expand in size on when in contact with a fluidand can return to original shape when not in contact with fluid. Whenfluid is collected inside housing and expandable material absorbs thefluid, the expandable material swells, and pushes the retainer to applyforce on a circumferential boundary portion of the membrane. Applicationof force on the circumferential boundary portion of the membrane tilts asecond umbrella member portion and allows drainage of fluid from insidehousing. The valve is self-actuatable, and drains fluid from inside thehousing after force is applied on the circumferential boundary portionof the membrane exceeds a certain threshold. Once fluid is drained frommodule, the absorbed liquid evaporates or is otherwise removed from theexpandable member and returns to its original size thereby closing thevalve. Preferentially, there is no need for external intervention forfunctioning of valve for the removal of the absorbed liquid.

In embodiments, a battery enclosure is disclosed. The battery enclosureincludes an enclosure. The battery enclosure includes a plurality ofcells housed inside the enclosure. The battery enclosure includes anumbrella member with a stem coupled to a housing. The battery enclosureincludes a retainer coupled to the enclosure, a holder and the umbrellamember. An expandable material is disposed within the holder. Theexpandable material is adapted to expand in size when absorbing a fluidand translate the umbrella member along an axis of the stem.

In embodiments, a method to assemble a valve into a battery system isdescribed. The method includes assembling a valve within a batteryenclosure, the valve having an umbrella member with a stem. The methodfurther includes providing an enclosure of the battery system, providingan opening defined by a surface of the enclosure of the battery system,positioning a retainer within the enclosure, coupling a holder to theretainer, positioning expandable material within holder, inserting thestem of the umbrella member into the holder, and positioning theumbrella member such that the umbrella member provides a liquid tightseal for the opening. The method may further include steps to disengagevalve from enclosure by twisting the valve to disengage a valve from theenclosure and pulling valve out of opening. Easy assembly anddisassembly steps make valve easily replaceable and convenient to use.In embodiments, the steps of coupling a holder to the retainer andpositioning expandable material within holder occur prior to positioninga retainer within the enclosure.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates a battery enclosure, according to certain embodimentsof the disclosure.

FIG. 2 illustrates a valve for use with housing of battery enclosure,according to certain embodiments of the disclosure.

FIG. 3A illustrates a cross-sectional view of the valve being used withhousing of battery enclosure, according to certain embodiments of thedisclosure.

FIG. 3B illustrates a cross-sectional view of the valve according tocertain embodiments of the disclosure.

FIG. 4 shows a cross-sectional view of a valve element of valve,according to certain embodiments of the disclosure.

FIG. 5 shows a bottom view of valve element, according to certainembodiments of the disclosure.

FIG. 6 schematically shows valve being used with housing in a nominalstate, according to certain embodiments of the disclosure.

FIG. 7 schematically shows valve being used with housing in an openstate, according to certain embodiments of the disclosure.

FIG. 8 shows a flow chart illustrating a method of assembling valve withhousing of battery enclosure, according to certain embodiments of thedisclosure.

FIG. 9 shows a state diagram of valve illustrating various scenarios,according to certain embodiments of the disclosure.

FIG. 10 shows a perspective view of valve, according to certainembodiments of the disclosure.

FIG. 11 shows a perspective view of valve of FIG. 10 without a cap,according to certain embodiments of the disclosure.

FIG. 12 shows a perspective view of valve of FIG. 10 without a cap and aseal, according to certain embodiments of the disclosure.

Embodiments of the present disclosure and their advantages are bestunderstood by referring to the detailed description that follows. Itshould be appreciated that like reference numerals are used to identifylike elements illustrated in one or more of the figures, whereinshowings therein are for purposes of illustrating embodiments of thepresent disclosure and not for purposes of limiting it.

DETAILED DESCRIPTION

FIG. 1 illustrates a battery system 100. Battery system 100 includesenclosure 102. Multiple cells 104 are housed inside enclosure 102 suchthat cells 104 may provide power as per application requirements. Anopening 106 is defined by a surface 108 of enclosure 102. Opening 106helps in draining any fluid from enclosure 102. Valve 110 is coupled toopening 106 such that valve 110 selectively allows drainage of fluidfrom enclosure 102. Valve 110 is designed such that valve 110 getsself-actuated under load of fluid accumulated inside enclosure 102, andallows passage of fluid afterwards. Once fluid is removed from enclosure102, valve 110 gets closed again on its own without any externalintervention. Appropriate passage may be provided for fluid passing outof enclosure 102, to prevent any spillage of fluid near battery system100.

FIG. 2 illustrates a perspective view of valve 110. Valve 110 includesan umbrella member 204 that has a stem with a curved top that resemblesan umbrella. Valve 110 is coupled to enclosure 102 when valve 110 isoperational. FIG. 3A shows a cross-sectional view of valve 110 coupledto enclosure 102. Umbrella member 204 includes a stem 302. Stem 302 hasa first end 304 and a second end 306. Umbrella member 204 is placedwithin a retainer 310 and holder 320, which also holds with expandablematerial 312 (not shown in FIG. 3). In embodiments, retainer 310contains a tab that helps retainer 310 couple to holder 320. Valve 110is inserted inside opening 106 of enclosure 102. In embodiments, stem302 further includes a conical washer. The conical washer may be aflexible component that extends away from stem 302. In embodiments, theconical washer constrains the expanding material. The conical washer maybe made of the same material as the stem 302 and/or umbrella member 204.In other embodiments, the conical washer is made of a different materialthan 302 and/or umbrella 204.

Valve 110 includes retainer 310. Retainer 310 couples to holder 320,which holds expandable material 312. Retainer 310 may also couple toenclosure 102. In embodiments, retainer 310 has expandable tabs to applypressure when retainer is coupled to enclosure 102, thereby lockingvalve 110 into enclosure 102. In embodiments, opening 106 in enclosure102 is circular with small expanded areas. In such an embodiment, thevalve 110 may be removed by rotating the valve 110 such that the forceon the expandable tabs is reduced when the rotation causes theexpandable tabs to reach expanded areas of opening 106.

The expandable material 312 held by holder 320 may be made up ofcellulose-based material, silica gel, sodium polyacrylate, otherhydroscopic polymers, or another expanding material. When in contactwith fluid, the expandable material 312 absorbs fluid and expands insize. Further, when the expandable material 312 is not in contact withfluid, the expandable material 312 loses absorbed fluid and contracts insize. In embodiments, the expandable material 312 is donut shaped, thatis circular with a center hole. In certain embodiments, the retainer 310has a portion that extends wider circumferentially than the membrane andcontains a spray shield 360 (spray shield shown in FIG. 3B). The sprayshield 360 is a member that extends around the circumference of themembrane and prevents fluid ingress from spray of any liquid fromunintendedly entering the battery enclosure (or other enclosure), forexample, when a user power washes the battery enclosure.

FIG. 4 illustrates further structural details of umbrella member 402.Umbrella member 402 has a stem 302 with second end 306 that resembles anumbrella. Second end 306 is coupled to first end 304 of stem 302, andextends substantially radially away from first end 304 of stem 302.Umbrella member 402 includes a first umbrella member portion 404 and asecond umbrella member portion 406, which together form a substantiallyconical shape of the umbrella member 402. First umbrella member portion404 extends radially away from first end 304 of stem 302. First umbrellamember portion 404 defines a circumferential boundary portion 408, whichhas a first diameter D₁.

Umbrella member 402 further includes second umbrella member portion 406.Second umbrella member portion 406 extends radially away fromcircumferential boundary portion 408 and has a second diameter D₂. Whenoperational, second umbrella member portion 406 extends fromcircumferential boundary portion 408 to enclosure 102, and sealsenclosure 102 to prevent passage of any fluid from inside of enclosure102 to outside of enclosure 102, as well as passage of any fluid fromoutside of enclosure 102 to inside of enclosure 102. Second umbrellamember portion 406 is adapted to be tilted on application of a force oncircumferential boundary portion 408 in a direction away from enclosure102. Direction of application of force is depicted by arrows 410.

For second umbrella member portion 406 to tilt relative to firstumbrella member portion 404 on application of force on circumferentialboundary portion 408, second diameter D₂ should be greater than or equalto a threshold tilting diameter D_(T). In other words, threshold tiltingdiameter D_(T) is defined as minimum value of second diameter D₂ forsecond umbrella member portion 406 to tilt relative to first umbrellamember portion 404 on application of force on circumferential boundaryportion 408. For example, a ratio of threshold tilting diameter D_(T)and first diameter D₁ may be between 1.4-3.0. In certain embodiments,the ratio may be greater than 3.0.

During operation, when the membrane pivots, the umbrella member may betranslated along the axis of the stem. In embodiments, a conical washerportion is located around the stem, which constrains the expandingmaterial. This constrains the valve in a closed manner until theexpanding material absorbs sufficient liquid to overcome the constraintand translate the valve along the axis from the pivoting of the membrane(and release fluid).

FIG. 5 shows a bottom view of valve element 202. Valve 110 includesumbrella member 402 having first umbrella member portion 404 and secondumbrella member portion 406. Circumferential boundary portion 408 offirst umbrella member portion 404 separates umbrella member 402 intofirst umbrella member portion 404 and second umbrella member portion406. An area of first umbrella member portion 404 is depicted by A₁, andan area of second umbrella member portion 406 is depicted by A₂. Secondarea A₂ is greater than first area A₁ to ensure valve 110 stays closedunder application of any external pressure. External pressure may becaused by any external flood around battery system 100. The FIG. 6schematically illustrates cross-section of valve 110 coupled toenclosure 102 of battery system 100. Valve 110 is illustrated as closed,and sealing opening 106 defined by surface 108 of enclosure 102. For thesake of clarity, enclosure 102 is only partially shown in FIG. 6. Holder320 with expandable material 312 is shown in contracted state insideenclosure 102. Retainer 310 is coupled to holder 320 such that retainer310 is in contact with both enclosure 102 and holder 320. When fluidgets inside enclosure 102 (for example, because of internal batteryrupture or a leak event), fluid may get filled inside enclosure 102. Insuch a scenario, expandable material 312 absorbs fluid and expands. Incertain embodiments, the retainer 310 has a portion that extends widercircumferentially than the membrane and contains a spray shield. Thespray shield is a member that extends around the circumference of themembrane and prevents any liquid from unintendedly entering the batteryenclosure (or other enclosure) by shielding liquid, for example, when auser power washes the battery enclosure.

FIG. 7 shows holder 320 with expandable material 312 in expanded state.When the expandable material 312 expands it causes umbrella member 402to translate along its axis from the pivoting of the umbrella member 402(and release fluid). As shown in FIG. 7, second umbrella member portion406 is tilted relative to first umbrella member portion 404, and allowsfluid to pass through opening 106.

FIG. 8 illustrates a method 800 of assembling valve 110 within batterysystem 100. Method 800 at step 802 includes providing enclosure 102 ofbattery system 100. Multiple cells 104 are housed inside enclosure 102of battery system 100. Method 800 at step 804 includes providing opening106 defined by surface 108 of enclosure 102 of battery system 100.Method 800 at step 806 includes positioning retainer 310 withinenclosure 102. Method 800 at step 808 includes coupling retainer 310 toholder 320, which is holding expandable material 312. In certainembodiments, step 806 is not included and the functionality of retainer310 is contained elsewhere, for example in enclosure 102. Retainer 310contacts both enclosure 102 and circumferential boundary portion 408 ofumbrella member 402. Method 800 at step 810 includes inserting first end304 of stem 302 of valve element 202 inside enclosure 102 throughopening 106. Step 812 includes positioning umbrella member 402 of valve110 such that umbrella member 402 provides a liquid tight seal foropening 106.

Method 800 may further include adjusting conical washer extending fromstem 302 relative to enclosure 102 to keep valve element 202 in placerelative to enclosure 102. Method 800 may further include steps todisengage valve 110 from enclosure 102 of battery system 100. Method 800may include twisting stem 302 to disengage conical washer from enclosure102. Disengaging conical washer allows valve element 202 to moverelative to enclosure 102. Method 800 may further include disengagingvalve element 202 from enclosure 102, and pulling out first end 304 ofstem 302 outside of enclosure 102 through opening 106 defined by surface108 of enclosure 102.

FIG. 9 shows various scenarios which may occur with respect to state ofvalve 110. At block 902, valve 110 is in nominal state. Nominal staterefers to valve 110 is in closed state, and expandable material 312 isin dry state. An exemplary scenario includes both internal flooding andexternal flooding of battery system 100. In such a scenario, valve 110switches to a first state. First state refers to valve 110 in closedstate, and expandable material 312 being wet due to internal flooding.Valve 110 does not allow any external fluid to pass inside enclosure 102due to external flooding. The pivot and the ratio of the diametersimpacts is preferentially chosen to prevent impingement of water (oranother liquid) during an external flooding event. For example, a ratioof threshold tilting diameter D_(T) and first diameter D₁ may be between1.4-3.0. In certain embodiments, the ratio may be greater than 3.0.During operation, when the membrane pivots, the valve may be translatedalong the axis of the stem. In embodiments, a washer portion is locatedaround the stem, which constrains the expanding material. Thisconstrains the valve in a closed manner until the expanding materialabsorbs sufficient liquid to overcome the constraint and translate thevalve along the axis from the pivoting of the membrane (and releasefluid).

If there is no more external flooding but internal flooding stillpersists, then valve 110 switches to a second state. Second state refersto valve 110 in open state, and expandable material 312 being wet due tointernal flooding. Initially, if there is only internal flooding and noexternal flooding, then valve 110 switches directly to second state. Asvalve 110 is open in second state, fluid may be passed outside ofbattery system 100 through open valve 110. When there is no moreflooding, either in first state or second state, battery system 100 mayeventually dry out, and valve 110 may return to nominal state.

If a thermal runaway event occurs, for example, cells rupture within abattery enclosure creating a large internal pressure, then valve element202 switches to a third state. Third state refers to valve 110 in openstate from the internal pressure of the generated. In third state,expandable material 312 has not absorbed much, if any, liquid. As valve110 is open in third state, gas may be passed outside of battery system100 through open valve 110. When the internal pressure of the gas withinthe battery enclosure has decreased, and is approximately the same asthe pressure outside of the module, valve 110 may close and return tonominal state.

FIGS. 10-12 show another structural configuration of valve 110. Valve110 includes a cap 1002 which covers internal components of valve 110.Cap 1002 may be retained with enclosure 102 through any suitablemechanical retaining means. In illustrated embodiment, cap 1002 includesmultiple grooves 1004 on an external surface 1006 of cap 1002. Enclosure102 includes multiple elastically deformable tabs 1008 such that tabs1008 engage with grooves 1006 and couple cap 1002 and enclosure 102together.

FIG. 11 shows valve 110 without cap 1002 to show internal structure ofvalve 110. Valve 110 include a seal 1102 coupled between cap 1002 andenclosure 102 to make sure any fluid does not enter from under cap 1002.Seal 1102 may be a gasket, or any other suitable sealing means which maybe suitable for application with aspects of present disclosure.

FIG. 12 shows valve 110 without cap 1002 and seal 1102. Valve 110includes expandable material 1202. Expandable material 1202 isillustrated as a stack of multiple non-circular shaped elements 1204.Non-circular shaped elements 1204 are provided with a central hole 1206such that expandable material 1202 may be placed around stem 302 ofvalve 110. In certain embodiments, expandable material 1202 is paper.Present disclosure is not limited by illustrated shape of non-circularshaped elements 1204. Non-circular shaped elements 1204 may have anynon-circular shape as per application requirements. Non-circular shapedelements are provided with slots 1208 on a periphery of eachnon-circular shaped element to increase surface area of expandablematerial 1202. Increased surface area provides better absorptioncharacteristics for expandable material, making valve function moreeffectively. In certain embodiments, expandable material 1202 has anintegral non-circular shaped structure.

Valve 110 further includes a spring 1210 coupled to enclosure 102.Spring 1210 has a helical structure such that spring 1210 is partiallywrapped around expandable material 1202. Multiple spacer elements 1212are provided between spring 1210 and expandable material 1202 to makesure expandable material 1202 remains in a compressed state. Forassembly of valve 110, expandable material 1202 in form of stack ofmultiple non-circular shaped elements 1204 is placed around stem 302 ofvalve 110. Spring 1210 is wrapped around expandable material 1202 withhelp of spacer elements 1212. Afterwards, cap 1002 and seal 1102 areprovided to cover internal components of valve 110.

The foregoing disclosure is not intended to limit the present disclosureto the precise forms or particular fields of use disclosed. As such, itis contemplated that various alternate embodiments and/or modificationsto the present disclosure, whether explicitly described or impliedherein, are possible in light of the disclosure. Having thus describedembodiments of the present disclosure, a person of ordinary skill in theart will recognize that changes may be made in form and detail withoutdeparting from the scope of the present disclosure. Thus, the presentdisclosure is limited only by the claims.

In the foregoing specification, the disclosure has been described withreference to specific embodiments. However, as one skilled in the artwill appreciate, various embodiments disclosed herein can be modified orotherwise implemented in various other ways without departing from thespirit and scope of the disclosure. Accordingly, this description is tobe considered as illustrative and is for the purpose of teaching thoseskilled in the art the manner of making and using various embodiments ofthe disclosed air vent assembly. It is to be understood that the formsof disclosure herein shown and described are to be taken asrepresentative embodiments. Equivalent elements, materials, processes orsteps may be substituted for those representatively illustrated anddescribed herein. Moreover, certain features of the disclosure may beutilized independently of the use of other features, all as would beapparent to one skilled in the art after having the benefit of thisdescription of the disclosure. Expressions such as “including”,“comprising”, “incorporating”, “consisting of”, “have”, “is” used todescribe and claim the present disclosure are intended to be construedin a non-exclusive manner, namely allowing for items, components orelements not explicitly described also to be present. Reference to thesingular is also to be construed to relate to the plural.

Further, various embodiments disclosed herein are to be taken in theillustrative and explanatory sense, and should in no way be construed aslimiting of the present disclosure. All joinder references (e.g.,attached, affixed, coupled, connected, and the like) are only used toaid the reader's understanding of the present disclosure, and may notcreate limitations, particularly as to the position, orientation, or useof the systems and/or methods disclosed herein. Therefore, joinderreferences, if any, are to be construed broadly. Moreover, such joinderreferences do not necessarily infer that two elements are directlyconnected to each other.

Additionally, all numerical terms, such as, but not limited to, “first”,“second”, “third”, “primary”, “secondary”, “main” or any other ordinaryand/or numerical terms, should also be taken only as identifiers, toassist the reader's understanding of the various elements, embodiments,variations and/or modifications of the present disclosure, and may notcreate any limitations, particularly as to the order, or preference, ofany element, embodiment, variation and/or modification relative to, orover, another element, embodiment, variation and/or modification.

It will also be appreciated that one or more of the elements depicted inthe drawings/figures can also be implemented in a more separated orintegrated manner, or even removed or rendered as inoperable in certaincases, as is useful in accordance with a particular application.Additionally, any signal hatches in the drawings/figures should beconsidered only as exemplary, and not limiting, unless otherwisespecifically specified.

What is claimed is:
 1. A valve comprising: a holder having an expandablematerial; a retainer coupled to the holder; a stem having a first endcoupled to the holder; and an umbrella member coupled to a second end ofthe stem; wherein the expandable material is adapted to expand in sizewhen absorbing a fluid thereby causing the umbrella member to betranslated along an axis of the stem.
 2. The valve of claim 1, whereinthe expandable material comprises a stack of non-circular shapedelements.
 3. The valve of claim 2, wherein the non-circular shapedelements define a plurality of slots disposed around a periphery of eachof the non-circular shaped elements.
 4. The valve of claim 3, whereinthe valve further includes a spring adapted to hold the stack ofnon-circular shaped elements in a compressed state.
 5. The valve ofclaim 1, wherein the umbrella member comprises: a first umbrella memberportion extending radially away from the stem, the first umbrella memberportion defining a circumferential boundary portion having a firstdiameter; a second umbrella member portion extending radially away fromthe circumferential boundary portion of the first umbrella memberportion, the second umbrella member portion having a second diameter;wherein the first umbrella member portion and the second umbrella memberportion together define a substantially conical shape of the umbrellamember; and wherein the second umbrella member portion is adapted to betilted relative to the first umbrella member portion on application of aforce on the circumferential boundary portion.
 6. The valve of claim 5,wherein an area of the second umbrella member portion is greater than anarea of the first umbrella member portion.
 7. The valve of claim 5,wherein the second umbrella member portion defines a threshold tiltingdiameter of the valve such that the second diameter should be greaterthan or equal to the threshold tilting diameter for the second umbrellamember portion to be tilted relative to the first umbrella memberportion on application of the force on the circumferential boundaryportion.
 8. The valve of claim 7, wherein ratio of the threshold tiltingdiameter and the first diameter is between 1.4 and 3.0.
 9. The valve ofclaim 5, wherein a structure of the valve defines a threshold tiltingdiameter of the valve such that the second diameter should be greaterthan or equal to the threshold tilting diameter for the second umbrellamember portion to be tilted relative to the first umbrella memberportion on application of the force on the circumferential boundaryportion.
 10. A battery enclosure comprising: an enclosure; a pluralityof cells housed inside the enclosure; a stem having a first end coupledto a housing; an umbrella member coupled to a second end of the stem; aretainer coupled to the enclosure, a holder and the stem; and anexpandable material disposed within the holder, wherein the expandablematerial is adapted to expand in size when absorbing a fluid therebycausing the umbrella member to be translated along an axis of the stem.11. The battery enclosure of claim 10, wherein the expandable materialcomprises a stack of non-circular shaped elements.
 12. The batteryenclosure of claim 11, wherein the non-circular shaped elements define aplurality of slots disposed around a periphery of each of thenon-circular shaped elements.
 13. The battery enclosure of claim 12,wherein the valve further includes a spring adapted to hold the stack ofnon-circular shaped elements in a compressed state.
 14. The batteryenclosure of claim 10, wherein the umbrella member comprises: a firstumbrella member portion extending radially away from the stem, the firstumbrella member portion defining a circumferential boundary portionhaving a first diameter; a second umbrella member portion extendingradially away from the circumferential boundary portion of the firstumbrella member portion, the second umbrella member portion having asecond diameter; wherein the first umbrella member portion and thesecond umbrella member portion together define a substantially conicalshape of the umbrella member; and wherein the second umbrella memberportion is adapted to be tilted relative to the first umbrella memberportion on application of a force on the circumferential boundaryportion.
 15. The battery enclosure of claim 14, wherein an area of thesecond umbrella member portion is greater than an area of the firstumbrella member portion.
 16. The battery enclosure of claim 14, whereinthe second umbrella member portion defines a threshold tilting diameterof the valve such that the second diameter should be greater than orequal to the threshold tilting diameter for the second umbrella memberportion to be tilted relative to the first umbrella member portion onapplication of the force on the circumferential boundary portion. 17.The battery enclosure of claim 16, wherein ratio of the thresholdtilting diameter and the first diameter is between 1.4 and 3.0.
 18. Amethod of assembling a valve with a battery enclosure, the valve havingan umbrella member coupled to a second end of a stem, the methodcomprising: providing an enclosure of a battery system; providing anopening defined by a surface of the enclosure of the battery system;positioning a retainer within the enclosure; coupling a holder to theretainer; positioning expandable material within holder; inserting afirst end of the stem into the holder; and positioning the stem andumbrella member such that the umbrella member provides a liquid tightseal for the opening.
 19. The method of claim 18, wherein the steps ofcoupling a holder to the retainer and positioning expandable materialwithin holder occur prior to positioning a retainer within theenclosure.
 20. The method of claim 18, further comprising: twisting thevalve to disengage a tab from the enclosure; and disengaging the valvefrom the enclosure.